Magnetisation Grade:         N38
Material: Neodymium-Iron-Boron (NdFeB), Neodymium and Steel 
Magnet ID:              NPH-50-N38-Ni
Plating / Coating: Nickel-plated (Ni) / Nickel (Ni-Cu-Ni) / Double Ni    
Shape: Ring / with Hook    
Pot Magnet Size: 
Pot diameter (D): 50 mm
Neck diameter (d): 9 mm
Pot height (H1): 15 mm
Total height without hook (H2): 20.5 mm
Total height with hook (H3):  68 mm
Thread (M): M4
Tolerance:         ±0.1 mm
Magnetisation Direction:   Axial      
Residual Magnetic Flux Density (Br): 12.2-12.6 KGs (T):  1.22-1.26 T 
Energy Density (BH)max:              35-39 MGOe   279-310 KJ/m³   
Coercivity Force (Hcb):              ≥10.8 KOe  ≥860 KA/m   
Intrinsic Coercivity Force (Hcj):    ≥12 KOe    ≥955 KA/m   
Maximum Operation Temperature: 80 °C 
Delivery Time:           14-35 days   
Measurements:

Magnetic Clips, Magnetic Hooks, Magnet Pots are made of magnets and steel iron
Features:
1) Made of iron, steel with sintered ferrite, sintered NdFeB and cast alnico gluing together
2) Sintered ferrite pot magnets and cast alnico pot magnets maintain their magnetic properties under extreme heat conditions, and are ideal for industrial requirements
3) For daily life use as holding magnets
Pros: Very strong hold when contacting another magnet or plain iron, very difficult to pull away (easy to slide however).
Pretty strong hold between two of these even with a couple of mm in between.
Cons: Would like thicker (and more powerful) versions. Sure u can stack these together but sometimes it's not the same thing.
Other Thoughts: Good for attaching thick stacks of paper to refrigerators etc or pinching together papers or textiles.
Bottomline: This is the one if you need strong cost-effective magnet.